Ultra energy-efficient cars[2] don’t always have to come with a high price tag. One upcoming vehicle from Renault-Nissan[3] and India’s Bajaj Auto[4] will, in fact, cost just $3,000 and reach an impressive 70 mpg. The Renault-Nissan Alliance has been working with Bajaj (India’s second-largest bike manufacturer) on development of the vehicle for two years, but the partners just signed a memorandum of understanding this past week.

[5]Bajaj prototype car photo by AP

The mini-car, nicknamed ULC (Ultra Low Cost, perhaps?), is expected to go on sale on India in 2011. Approximately 200,000 cars are expected to be sold each year.

Of course, the Bajaj/Renault-Nissan car won’t be the only efficient, low-cost vehicle on India’s roads. The Tata Nano[6], which costs just $2,160, gets 51.7 mpg on city road conditions and 61.1 mpg on highways. So while the Nano is a bit cheaper, the Bajaj car will win out on efficiency — at least until Tata releases an electric model[7].

We just have one question: when will the battle of the cheap, efficient vehicles migrate to the U.S. and Europe?